2B

2B or II-B may refer to:
* 2B (band), a musical duo who represented Portugal in the Eurovision Song Contest 2005
* Alpha-2B adrenergic receptor
* Stalag II-B, a prisonners of war camp in Germany
* Transcription Factor II B

and also:
* a degree on the scale of pencil lead hardness
* Aerocondor IATA airline code
* second base, in baseball
** a double (baseball) in baseball
* The number of the French department Haute-Corse